211? Or 845? Which one do you prefer? – Product Review


Yarland PRO-845SE IV integrated electron tube amplifier

● Output power: 25W

● Frequency response: 15Hz~30kHz (+/-1dB)

● Operating mode: single-ended class A amplifier

● Signal to noise ratio: 89dB

● Electron tube being applied: 5Z4P x 1, 12A x 7 x 1, 6N8P x 2

● 845 × 2 (or, choose 211 x 2 or 805 x 2)

● Input impedance: 100kΩ

● Dimension (H * W * D): 160 x 320 x 400mm

● Weight: 29kg

● Reference price:

● Website: www.yarland.com

● Advantages: 3 different models of the electron tube version including 211, 805 and 845 are available with a variety sound in different styles

● Expectation: the 16 ohm output Impedance port is available

The adjustment of the bias voltage matters most whichever version is applied

The PRO-845SE IV is a kind of the electron tube amplifier that provides 3 versions of the power tube. Therefore, the adjustment of the bias voltage matters most, which makes the electron tube work within the specific range, no matter which version of the power amplifier is chosen by fanciers. The power amplifier of the PRO-845SE IV possesses 2 adjusting knobs including the “BIAS” and the “HUM”. Adjust the potentiometer of the BIAS of the original electron tube to make the indication on the display become 0.3V, and power off the device to change the electron tube after the completion. The adjustment of the BIAS still needs to continue when the electron tube is changed until the indication on the display is between 0.62~0.65V, which is a normal value. In addition, the potentiometer of the Hum also needs to be adjusted with a simple method. To adjust the potentiometer of the Hum slowly so as to obtain the lowest noise made by the stereo equipment indicates the completion of the adjustment. You can begin your music journey afterwards!

“To amuse oneself with the electron tube amplifier is to remodel the amplifier”. This is the most appropriate phrase to depict fanciers for electron tube amplifiers. I know many fanciers of the electron tube amplifier, 99% of which are fond of remodeling. Why? Because the circuit of the electron tube amplifier, the replacement of components or the alteration of the circuit are very simple with great possibility for modification. As for the primary fancier, they like to use components including the electron tube, the capacitor and the resistor in different brands, while part of fanciers are the old hand in the technique who like to alter the circuit design, or imitate the circuit of a famous device to DIY a new one for themselves. In brief, they are willing to do anything to improve the tone quality of the electron tube amplifier, and you can not imagine how frenzied they are.

As for the manufacturer of the electron tube amplifier, designers also understand fanciers’ mentality mentioned above, so they design many appropriate products for fanciers. One of the representative is the PRO-845SE IV electron tube amplifier produced by Yarland, which produces models in 845, 211 and 805 version for consumers to amuse themselves extremely! For there are 3 different versions of PRO845SE IV models, I choose 845 version and 211 version specially for listening to appreciate different “tastes” of the electron tube!

The terminal of two output impedance specifications of 4Ω and 8Ω are provided at the rear of the PRO845SE-IV

The adjustment function of BIAS and HUM is set on the roof of the electron tube amplifier. I recommend buyers to adjust these two parameters before using. In addition, the amplifier needs to be adjusted after being used for a period of time

The 211 version and 845 version of the PRO845SE-IV are identical in shape with the only difference on the power tube

The power tube of the power amplifier in either the 211 version or the 845 version is produced by PSVANE Electron Tube Factory

Want to listen to delicate, sweet, and spiritual sound” Please use 211!

I listen to the PRO-845SE IV this time with the original power tube of 211, and I believe senior fanciers are familiar with this. I use PRO-845SE IV to drive the stereo equipment of JBL 4312D with an excellent sound, for the sound made by JBL 4312D is delicate and clear with explicit sense of line, while the sound made by 211 is also spiritual, sweet and warm. Therefore, the combination of these two produces clear and sweet features with medium high frequency and sound extending excellently. When the “Mozart: String Quartet No.3 and No.4” by Alban Berg Quartet has been replayed in the device, the sound of instruments is cohesive with clear and distinct sense of line, and the quality of instruments is excellent, because you can clearly hear the sound of friction made by the violin and the cello with warm tonality and pliability, which makes the sound flexible with special qualities. However, if you listen to the “Voices of Spring Waltz” from the “New Year’s Concert in Vienna 1987”, you can hear the high frequency of the soprano going natural and smooth with great fluency, which sounds relaxed and natural instead of depressed. As for the driving force, the strengths of PRO-845SE IV are to represent the cohesiveness of sound and the expressiveness of music in detail rather than producing abundant low frequency and powerful output acoustic pressure, especially the expressive ability on quartet and female voice. The natural and fluent sense of the music replayed in PRO-845SE IV by 211 electron tube is very attractive.

The strength of 845version is enhanced with the resounding sound

After trying the original 211, it is the time for 845 version of PRO845SE I. In contrast, after hearing, the power amplifier of 845 version focusing on the sound in medium-frequency and low-frequency stage producing the resounding sound, when the “Mozart: String Quartet No.3 and No.4” by Alban Berg Quartet has been replayed in the device, the acoustic image becomes larger significantly, especially the stronger acoustic resonance of the violin family, whose shape enlarges therewith. While the band sound in the “Voices of Spring Waltz” possesses the sense of scale, the low frequency of the cello and the timpani carries weight with the decorous feeling. In the meanwhile, the human voice relatively thickens, which produces the sense of modesty for listeners as a whole.

Certainly, the pop music and the jazz replayed by the device bring the best result. The album called “True Love Expression” sang by Jacky Cheung is one of the most familiar records by me, while the song called “Love” replayed by PRO845SE IV with 845 electron tube is full of passion, of which you can hear the clear and melodious sound of the electric guitar rather than sharp, you can feel the powerful and flexible strength of the low-frequency played by the drum set, and you can also sense the dynamic and powerful human voice. When sing the high key, you do not feel depressed either, and the sense of rhythm and warm tonality make me comfortable and enjoyable. While listening to the song called “Take Five” from the “Time Out” album, you can feel the relaxed and natural sound with excellent loose low frequency, and the ability of cohesiveness and the channel separation are excellent, which can be described as well defined.

211? 845? How to choose?

As for this kind of electron tube amplifier with different electron tube version in different models, fanciers will wonder what is the difference between 211, 845 and 805? Is there any advice or products recommended to match? Actually, it is ideal for you to buy all of them when conditions allow you to find the famous and cool electron tune amplifiers. As for me, however, I would like to buy 211 and 845, the sound produced by which has met my requirements completely, because the sound made by 211 is delicate and sweet with excellent and spiritual medium and high frequency, while the sound made by 845 is resounding with powerful and dynamic medium and high frequency. In general, I prefer to choose 211 version for I am fond of its sweet and stretched sound, which produces great tone quality and excellent timbre by replaying jazz music, string music, quartet, quintet and so on. As for the amplifier of 845 version, it is adaptable to music with strong decorous feeling, which can be used to replay the recording of the symphony music to satisfy your addition in music.

View Point


View Point

The prominent feature of PRO845SE IV is that it provides 3 different models of the electron tube version including 211, 845 and 805 with 3 models providing different sound styles. It is a great choice for fanciers of the electron tube amplifier.